In the afternoon we moved on, descending the little stream on which we had halted for dinner. Like the small branches of the Platte, it is inhabited by great numbers of beavers; but it has more timber, and a more fertile soil than any stream of similar magnitude we had lately passed. Some light showers occurred in the middle of the day, and at evening a thunder-storm was observed, in the same manner {206} as on the preceding day, to collect in the east, and after we had listened to its thunders for some time, it moved off in the direction of the Arkansa, but no rain fell where we were. In the course of the day several elk were seen, and at evening we killed an antelope. Robins are here frequent, and a jerboa was seen resembling the gerbillus canadensis; many fine plants were collected, several of which are hitherto undescribed.[151] [151] One of these is a large and conspicuous plant of the natural family of the _Cruciferæ_, which may be referred to the new genus, Stanley of Nuttall, and distinguished as S. _integrifolia_; stem simple, leaves entire, ovate oblong, tapering to both ends; stem angular. Flowers in a terminal raceme, which is a little branched below; about six inches in length; stipe of the silique, about as long as the pedicle; flowers large yellow. The whole plant, seen at a little distance, has a remote resemblance to Lysimachia thyrsifolia. The leaves are ⅚ inches long, ⅔ wide, glaucous, and veined, nearly resembling those of the common cabbage, but smoother, which they are not wholly unlike in taste. The calyx is large, and of a brighter yellow than the other parts of the flower: it inhabits the summits of the sandstone ridges, along the base of the mountains. The S. _pinnatifida_, N., the original type of this genus, was found by its discoverer, Mr. Nuttall, to act as a violent emetic. It had been eaten by several of the party who accompanied him, as a substitute for cabbage.—JAMES. Towards evening, our guide discovered we had already passed considerably beyond the base of the peak, near which it had been our intention to halt. He also perceived at the same moment, he had arrived at the very spot where some years ago he had been made prisoner by a party of Spaniards, who took him to Santa Fé.[152] As we were particularly desirous of visiting the mountains at the point designated in many maps as the highest "peak," we resolved to return upon our course, but as it was now near sunset, we thought it advisable to encamp for the night. [152] He was probably a member of the party of Chouteau and De Munn, arrested in 1817. See _ante_, note 134.—ED.